Apparatus for detecting wraps on processing rolls

ABSTRACT

An apparatus for detecting wraps on processing rolls that includes a piston and cylinder assembly connected to a water supply. One end of the piston rests against an extension tab projecting from a deflectable feeler assembly. Formation of a wrap causes the feeler assembly to move away from the roll surface and the tab away from the piston unseating the piston to cause a sudden drop in water pressure which is sensed by a pressure switch that in turn drops out a relay which stops a motor driving the processing roll. Removal of the wrap permits reseating of the piston.

United States Patent 1 Bowen my 3,820,699 June 28, 1974 APPARATUS FOR DETECTING WRAPS ON PROCESSING ROLLS [73] Assignee: E. I. du Pont de Nemours and Company, Wilmington, Del.

[22] Filed: Mar. 27, 1973 [21] App]. No.: 345,313

[52] US. Cl 226/43, 226/11, 226/25,

[51] Int. Cl. B65h 25/32 [58] Field of Search 226/25, 43, 45, ll; 242/36, 37

[5 6] References Cited UNITED STATES PATENTS 3,456,857 7/1969 Kneib 226/25 3,512,690 5/1970 Fisher ..226/25X Primary Examiner-Richard Schacher [5 7] ABSTRACT An apparatus for detecting wraps on processing rolls that includes a piston and cylinder assembly connected to a water supply. One end of the piston rests against an extension tab projecting from a defiectable feeler assembly. Formation of a wrap causes the feeler assembly to move away from the roll surface and the tab away from the piston unseating the piston to cause a sudden drop in water pressure which is sensed by a pressure switch that in turn drops out a relay which stops a motor driving the processing roll. Removal of the wrap permits reseating of the piston.

4 Claims, 2 Drawing Figures FIG ' APPARATUS FOR DETECTING WRAPS ON PROCESSING ROLLS I BACKGROUND or THE INVENTION The problem of roll wraps in textile winding operation is long standing and serious. Particularly for heavier strands such as ropes, an unchecked wrap may quickly cause the destruction of heavy expensive machinery as well as endanger operators nearby.

SUMMARY OF THE INVENTION An apparatus for detecting roll wraps of a flexible material being advanced by the roll thenstopping the roll upon detecting a wrap, said apparatus comprising: a roll for advancing the material; means for driving said roll; a feeler means mounted adjacent said roll for movement away from the roll; an extension projecting from the feeler means; means for biasing said feeler means toward said roll into a position of contact therewith; a source of pressurized fluid; means connected to the source of pressurized fluid for reducing the pressure of said fluid, said extension operatively engaging said means for reducing the pressure of said fluid to prevent operation thereof and maintain the pressure of said pressurized fluid; and a pressure switch connected between said means for driving the roll and said source of pressurized fluid for stopping the driving means, said switch being actuated to stop said driving means by a reduction in fluid pressure, whereby a wrap on said roll moves said feeler means away from said roll and said extension away from the pressure reducing means causing operation thereof to reduce said pressure of said pressurized fluid and actuate said switch.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an illustration of the wrap detector device of this invention partlyin cross section and in association with a draw roll; and

FIG. 2 is a schematic ofthe hydraulic circuit with one or more wrap detectors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 28 is journaled to the roll support frame by means of bearings not shown. An arm 25 is fixedto shaft 28 and arranged to receive counterweights 27 to bias blade22 against roll 10. A tab 30 projects out from holder 24 and is arranged to contact the outer end of a piston 42 which is a component of sliding valve assembly 40. Piston 42 is seen to comprise a larger cylindrical section 43 extending fromthe location of tab 30 to within the valve body 50 and to have a projection 44 of smaller diameter. Near the inner end of projection 44 an 0" ring seal 46 is placed in a slot around this end. The valve body has a larger diameter bore 51 loosely fitting piston section 43, a funnel shaped bore 52 which connects bore 51 to a smaller diameter bore 53 sized so that 0" ring 46 on projection 44 provides a hydraulic seal when projecting therein. Valve body 50 has a threaded valve intake bore 54 projecting from its outer surface into bore 53 and an outlet bore 56 projecting out from bore 51.

As shown in FIG. 2, bore 54 is connected by hydraulic tubing line 60 to a four-way connector 61. A hydraulic line 62 connects one outlet of connector 61 to a pressure switch 64. The electrical contacts of switch 64 are connected over cable 65 to a relay located in a conventional manner in the power supply circuit of the motor (not shown) for the draw machine rolls. A third hydraulic line 66 projects from connector 61 through a limiting orifice arrangement 67 to a line 68 which in turn connects through a valve 69 to the process feed water line 70 of the draw machine.

In operation, blade 22 rides adjacent the surface of draw roll 10 and when a roll wrap occurs, the wrap forces blade 22 away from the surface of the draw roll, thus rotating the holder 24 about shaft 28 such that tab 30 is moved away from piston 42. so that 0 ring seal 46 slides out of bore 53 into funnel shaped bore 52 (FIG. 1) allowing water to flow from intake 54 through bore 53 and out through bore 56, thus, reducing the pressure in line 60. This in turn reduces the pressure at the .pressure switch 64 and, consequently, switch 64 provides a stop signal over electrical line 65. In a preferred embodiment, pressure switch 64 is a Weatherite Model 4NN-K45 manufactured by the Static O Ring Company. Water under pressure is supplied from the process feed water line 70 for the draw machine through valve 69 and limiting orifice 67 to line 66. In a case of multiple process arrangements where several wrap detectors are needed, they may be connected over similar lines 60 60"" over hydraulic line 66' connected to the fourth outlet of four-way connector 6] which otherwise would be plugged.

Thus, a comparatively simple and very reliable wrap detector is provided which not only works in a very wet, corrosive atmosphere but employs the same water supply used'in the processing of the textile material. This invention provides the further advantage that the electrical components of this system may be located at a distance from the wet environment. thus, increasing the reliability of the overall system. The ease with which multiple detectors may be added furnishes a further advantage.

This invention is described in its preferred embodiment wherein available process feed water is used in connection with the sliding valve. Other sources of pressurized hydraulic liquids or air could be substituted and other variations in the structure would be apparent to those skilled in the art without departing from the spirit of the present invention. For example, a feeler bar, in place of the doctor blade assembly, might be mounted adjacent the roll surface and arranged for linear or angular deflection against a biasing spring, counterweight or pneumatic piston in the event of a roll wrap. The feeler bar mounting arrangement would then carry an extension tab arranged to engage a means for reducing fluid pressure as previously noted.

What is claimed is:

1. An apparatus for detecting roll wraps of a flexible material being advanced by the roll then stopping the roll upon detecting a wrap, said apparatus comprising:

a roll for advancing the material;

means for driving said roll;

feeler means mounted adjacent said roll for movement relative to said roll;

an extension projecting from the feelei'. means for movement in unison therewith;

means for biasing the feeler means toward said roll into a position adjacent thereto;

a source of pressurized fluid;

means connected to the source of pressurized fluid for reducing the pressure of said fluid, said extension operatively engaging said means for reducing the pressure of said fluid to prevent operation thereof and maintain the pressure of said pressurized fluid; and

a pressure switch connected between said means for driving the roll and said source of pressurized fluid for stopping the driving means, said switch being actuated to stop said driving means by a reduction in fluid pressure, whereby a wrap on said roll moves said feeler means away from said roll and said extension away from the pressure reducing means causing operation thereof to reduce said pressure of said pressurized fluid and actuate said switch.

2. The apparatus as defined in claim 1, said feeler means comprising: a doctor blade in a holder mounted on a shaft journaled in a fixed frame adjacent the roll and said extension comprising a tab projecting from the shaft for angular movement therewith.

3. The apparatus as defined in claim 1, said means for reducing pressure comprising a piston and cylinder assembly connected to the source of pressurized fluid, said piston being seated against said cylinder to contain said fluid and unseated to release said fluid, said extension engaging said piston to seat said piston against said cylinder.

4. The apparatus as defined in claim 1, said material being a textile fiber, said fluid being water. 

1. An apparatus for detecting roll wraps of a flexible material being advanced by the roll then stopping the roll upon detecting a wrap, said apparatus comprising: a roll for advancing the material; means for driving said roll; feeLer means mounted adjacent said roll for movement relative to said roll; an extension projecting from the feeler means for movement in unison therewith; means for biasing the feeler means toward said roll into a position adjacent thereto; a source of pressurized fluid; means connected to the source of pressurized fluid for reducing the pressure of said fluid, said extension operatively engaging said means for reducing the pressure of said fluid to prevent operation thereof and maintain the pressure of said pressurized fluid; and a pressure switch connected between said means for driving the roll and said source of pressurized fluid for stopping the driving means, said switch being actuated to stop said driving means by a reduction in fluid pressure, whereby a wrap on said roll moves said feeler means away from said roll and said extension away from the pressure reducing means causing operation thereof to reduce said pressure of said pressurized fluid and actuate said switch.
 2. The apparatus as defined in claim 1, said feeler means comprising: a doctor blade in a holder mounted on a shaft journaled in a fixed frame adjacent the roll and said extension comprising a tab projecting from the shaft for angular movement therewith.
 3. The apparatus as defined in claim 1, said means for reducing pressure comprising a piston and cylinder assembly connected to the source of pressurized fluid, said piston being seated against said cylinder to contain said fluid and unseated to release said fluid, said extension engaging said piston to seat said piston against said cylinder.
 4. The apparatus as defined in claim 1, said material being a textile fiber, said fluid being water. 